<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>bootstrap</title>
    <link rel="stylesheet" href="css/bootstrap.min.css">
    
</head>
<body>
<!-- <div class="container">
    大于等于768px显示
    <img src="img/1.webp" alt="" class="hidden-xs">
    小于768px显示
    <img src="img/2.webp" alt="" class="visible-xs">
</div> -->

<div class="container">
    <p class="visible-md visible-lg">大屏幕</p>
    <p class="visible-sm">中屏幕(ipad)</p>
    <p class="visible-xs">小屏幕(手机)</p>
</div>
</body>
</html>